Webhook events

This page is the reference for what Sequence sends and how. For a step-by-step integration walkthrough, see Set up webhooks.

Request format

Sequence delivers webhooks as POST requests with Content-Type: application/json. Every payload has the same envelope:

{
  notificationType: string;
  sequenceAccountId: string;
  resourceType?: string;
  resourceId?: string;
  resource?: Record<string, any>;
}

The resource field contains the state of the resource that triggered the event.

Example payload

A BILLING_SCHEDULE_CREATED delivery looks like this. The prices and phases arrays are simplified for readability; in real deliveries they contain the full pricing and phase structure for the schedule.

{
  "notificationType": "BILLING_SCHEDULE_CREATED",
  "sequenceAccountId": "019e6eb6-db30-7cf2-8017-06a5a2859e13",
  "resourceType": "BillingScheduleResponse",
  "resourceId": "019e6eb6-cd26-74eb-808b-e7a37f1c4ef1",
  "resource": {
    "id": "019e6eb7-0c24-765b-8446-6fb074f018d7",
    "status": "DRAFT",
    "startDate": "2026-04-27",
    "endDate": "2027-04-26",
    "customerId": "019e6eb7-353e-7ddf-a5ae-75f2d9509d6b",
    "recurrenceDayOfMonth": 1,
    "autoIssueInvoices": false,
    "rollUpBilling": false,
    "defaultDueDateDays": 30,
    "prices": [],
    "phases": [],
    "taxRates": [],
    "attachmentAssets": [],
    "integrationIds": [],
    "createdAt": "2026-04-27T17:04:11.601533Z",
    "updatedAt": "2026-04-27T17:04:11.601533Z"
  }
}

`Sequence-Signature` header

Every webhook includes a Sequence-Signature header containing a timestamp and an HMAC signature:

Sequence-Signature: t=1748866120822,s=6be6887a470c20978427ff89941ebecb83b2804ceed66fd93b3afc00de2e9f11

t is the delivery timestamp, in Unix milliseconds.
s is an HMAC-SHA256 signature of ${t}.${rawBody}, computed using the webhook’s signing secret.

The timestamp is part of the signed payload, so receivers can reject deliveries with a stale t to mitigate replay attacks. For working verification code, see Verify the signature in the integration guide.

Delivery

Acknowledgement. Sequence considers any 2xx response a successful delivery.
Retries. Any non-2xx response causes Sequence to retry. Retries continue for up to 24 hours, with exponential backoff.

New event types may be added over time. Handlers should accept and ignore types they don’t recognise.

Event catalog

Event	Resource type	Triggered when
`CUSTOMER_CREATED`	Customer	A customer is created
`CUSTOMER_UPDATED`	Customer	A customer is updated
`CUSTOMER_ARCHIVED`	Customer	A customer is archived
`INVOICE_CREATED`	Invoice	An invoice is created
`INVOICE_ISSUED`	Invoice	An invoice is issued
`INVOICE_UPDATED`	Invoice	An invoice is updated
`INVOICE_REMINDER_SENT`	Invoice	A dunning payment reminder is sent to a customer
`BILLING_SCHEDULE_CREATED`	BillingSchedule	A billing schedule is created
`BILLING_SCHEDULE_UPDATED`	BillingSchedule	A billing schedule is updated
`BILLING_SCHEDULE_ARCHIVED`	BillingSchedule	A billing schedule is archived
`CREDIT_NOTE_CREATED`	CreditNote	A credit note is created
`CREDIT_NOTE_UPDATED`	CreditNote	A credit note is updated
`CREDIT_NOTE_ISSUED`	CreditNote	A credit note is issued
`QUOTE_PUBLISHED`	Quote	A quote is published
`QUOTE_SIGNED`	Quote	A quote is signed
`QUOTE_ACCEPTED`	Quote	A quote is accepted
`MERCHANT_UPDATED`	Merchant	Merchant-level settings are updated
`WATCHTOWER_TASK_ASSIGNED`	WatchtowerTask	A Watchtower review task is assigned to a user

API Reference

Latest Live API

Version 2024-07-30

Request format

Example payload

`Sequence-Signature` header

Delivery

Event catalog

​Request format

​Example payload

​Sequence-Signature header

​Delivery

​Event catalog

Request format

Example payload

`Sequence-Signature` header

Delivery

Event catalog